My DIC says the front tires are 28# and the rears are 33#. My little hand held dial gauge say the fronts are 33# and the rears are 37#. Anybody got any info on which might be more accurate, and does it matter that the fronts are a little less than the rears?

Check them after car sets over night in the morning. I went through this shit for a week. LOL Set them at 36 (SS) ? (ZL1) reset the dic and drive a few miles. Your dic will show higher numbers as the tires get hotter from driving. Again check them in the morning if your car is in a garage. Hope this helps man... Go to Advance and get a digital gauge. Get a good one.

According to the owners manual, they should all be at 36psi cold.... I noticed my manual tire gauge was always about 5psi off from the DIC. Got a new manual gauge, and it matched. I now go with the DIC (had some big issues after rims changed, and after going through deep standing water.... now resolved, but I was testing it a LOT during that timeframe.)

According to the owners manual, they should all be at 36psi cold.... I noticed my manual tire gauge was always about 5psi off from the DIC. Got a new manual gauge, and it matched. I now go with the DIC (had some big issues after rims changed, and after going through deep standing water.... now resolved, but I was testing it a LOT during that timeframe.)

I'd trust the handheld gauge more than the DIC. My handheld gauge is always about 3-4 psi more.
I think GM intentionally shows a lower psi on the DIC. This makes owners pump up their tires way before the tires are dangerously underinflated.

Short of that, at least use the same gauge whenever you re-inflate the tires and don't be too afraid to experiment with slightly higher or even lower indicated pressures (since you won't know if your hand-held reads high or low unless you go get it calibrated somehow).

Don't be afraid to try a little stagger in your pressures either. A little more pressure in the fronts (2 or 3 psi) will make the car respond a little more crisply to steering wheel inputs, and setting the rears to a little less than the fronts gives them a little more margin against the car's tail "going loose" under a little too much throttle on corner exit. You might find that you prefer the car's handling behavior that way.

Short of that, at least use the same gauge whenever you re-inflate the tires and don't be too afraid to experiment with slightly higher or even lower indicated pressures (since you won't know if your hand-held reads high or low unless you go get it calibrated somehow).

Don't be afraid to try a little stagger in your pressures either. A little more pressure in the fronts (2 or 3 psi) will make the car respond a little more crisply to steering wheel inputs, and setting the rears to a little less than the fronts gives them a little more margin against the car's tail "going loose" under a little too much throttle on corner exit. You might find that you prefer the car's handling behavior that way.

Thanks for all the tips. I have a few dial gauges (not very expensive) and they all read the same so I'm betting the DIC is off. I will probably invest in more accurate tool just for my piece of mind. I also intend to take the advice and try a couple of different pressures to see what works best for me.

It cannot be any more accurate than how well within the permissible electrical and physical/mechanical tolerances the bits inside your specific sensors are. And that's assuming that all of your sensors are fully within spec.